CODEWITHSUNDEEP
c++
alex108
alex108

Reputation: 387

getting array index from a function

i've been assigned to write a program in C++ that, given an array of integers, finds the smallest (including its index) and largest number, and their subtraction. To do this, i decided to write three functions for each operation and it works perfectly. The problem is i don't know how to get the index of the smallest number.

I tried solving the problem by creating a variable and putting in inside a for loop and then print it. However, the program always says the index is 0.

Here you can see an example of how the output should be:

int myvector[200] = {40, 250, 9, 50} // Array containing 4 numbers

It should output: 

The smallest number is: 9 at index 2
The largest number is: 250
Their subtraction is: 241

Here you can see my code: 

#include <iostream>
#include <stdlib.h>
#include <stdio.h>

using namespace std;

int find_smallest (int myvector[], int smallest, int index){

    smallest = myvector[0];
    index = myvector[0];
    for(int i=0; i<4; i++) {
        if(myvector[i] < smallest) {
            smallest = myvector[i];
            index = i;
        }
    }

    return smallest;
}


int find_largest (int myvector[], int largest) {

    largest = myvector[0];
     for(int i=0; i<4; i++) {
        if(myvector[i] > largest) {
            largest = myvector[i];
        }
    }

    return largest;
}

int sub_minmax (int myvector[], int subtraction, int smallest, int largest){

    subtraction = largest - smallest;
    return subtraction;
}

int main()
{

    int myvector[200], smallest, largest, subtraction, index;

    for(int i=0;i<4; i++) {
        cout<<"Enter the number " <<i+1<<endl;
        cin>>myvector[i];
    }

    smallest = find_smallest(myvector, smallest, index);
    largest = find_largest(myvector, largest);
    subtraction = sub_minmax(myvector, subtraction, smallest, largest);

    cout<<endl;
    cout<<"the smallest number is: "<<smallest<<" at index "<<index<<endl;
    cout<<"the largest number is: "<<largest<<endl;
    cout<<"the substraction is: "<<subtraction<<endl;

    return 0;
}

Any help will be appreciated, thanks

Upvotes: 1

Views: 52

Answers (2)

srilakshmikanthanp
srilakshmikanthanp

Reputation: 2399

change this 

int find_smallest (int myvector[], int smallest, int index)

to 

int find_smallest (int myvector[], int smallest, int &index)

here index is not local variable it reference to value passed, so any changes in index in function reflect is original value.

if you want to return both you can use struct or class.

Upvotes: 1

Eraklon
Eraklon

Reputation: 4288

Pass index by reference.

int find_smallest (int myvector[], int smallest, int &index)

Upvotes: 1

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